Abstract

To prevent the interruption of the carbon cycle by the disposal of waste to landfills, organic kitchen
waste requires proper treatment such as composting to reduce its uncontrolled degradation on disposal sites and
subsequent greenhouse gases, odour emissions and nutrient losses. This study investigated the effects of bulking
agent, newspaper and onion peels, composting waste load sizes of 2 and 6 kg, or the use of starter culture on
kitchen-waste composting consisting of nitrogen-riched substrates, vegetable scraps and fish processing waste in
an in-vessel system. The optimised formulation of kitchen waste mixture was used for a 30-day composting study,
where the temperature profiles were recorded and the carbon-to-nitrogen ratios were measured as an indication of
compost maturity. The kitchen-waste composting process was conducted in parallel in two fabricated kitchen
waste composters.